2005/04/29 by Atsushi Horikoshi, Kenichi Kinugawa
Physics and Astronomy · #Nonlinear Waves and Solitons #Quantum, superfluid, helium dynamics #Spectroscopy and Quantum Chemical Studies #cond-mat.stat-mech #hep-th #quant-ph
paper · pdf · doi:10.1063/1.1888576
published as J.Chem.Phys. 122 (2005) 174104 · REVTeX4, 18 pages, 9 eps figures
openalex publication_date 2005/04/29 · arxiv created 2005/05/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We apply the effective potential analytic continuation (EPAC) method to the calculation of real time quantum correlation functions involving operators nonlinear in the position operator q. For a harmonic system the EPAC method provides the exact correlation function at all temperature ranges, while the other quantum dynamics methods, the centroid molecular dynamics and the ring polymer molecular dynamics, become worse at lower temperature. For an asymmetric anharmonic system, the EPAC correlation function is in very good agreement with the exact one at t = 0. When the time increases from zero, the EPAC method gives good coincidence with the exact result at lower temperature. Finally, we propose a simplified version of the EPAC method to reduce the computational cost required for the calculation of the standard effective potential.